Field of the Invention
The present invention relates to an ejection controller of a molded article ejection device, such as an ejector, for an injection molding machine.
Description of the Related Art
In starting molding operation or adjusting molding conditions in an injection molding machine, an operator may sometimes open a safety door that covers the injection molding machine, and then remove molded articles and check them for condition.
In conventional techniques, molded articles are checked after they are ejected by an ejector. If a large number of molded articles are handled, in particular, it may not be easy to identify the cavity in which the article ejected and dropped last is molded.
Japanese Patent Application Laid-Open No. 2000-52383 discloses a technique in which molded articles are removed by a molded article removing machine after a mold supported on a mold clamping device is opened. In doing this, a movable mold half is moved in its opening direction as the molded articles are ejected in a molded article holding position of the movable mold half. Thus, the simultaneously ejected molded articles can be held by the molded article removing machine.
In the technique disclosed in the patent document described above, however, the molded article removing machine is needed to remove the molded articles, so that it may sometimes be troublesome to check the molded articles for condition.
Japanese Patent Application Laid-Open No. 2002-144383 discloses a technique in which a mold release force is obtained from the difference between a load applied to an ejector mechanism driven without performing molding and a load applied to the ejector mechanism driven while performing molding, in order to measure an accurate mold release force in an injection molding machine.
In the technique disclosed in the patent document described above, however, an operator cannot check molded articles for condition, although the mold release force of the ejector mechanism in the injection molding machine can be accurately measured based on the load applied to the ejector mechanism.
Japanese Patent Application Laid-Open No. 2011-136512 discloses a technique in which an optimal retract end position of an ejector is detected and set to prevent breakage of an ejector device or a mold or extension of the molding cycle time that may lower the production efficiency.
In the technique disclosed in the patent document described above, however, an operator cannot check molded articles for condition, although the retract end position of the ejector mechanism in the injection molding machine can be accurately set.